MONDAY, Oct. 1, 2007 (HealthDay News) -- Breast-feeding will not ratchet up the risk of toddler tooth decay, new research claims.
Cavities affect one in four young children, but the contributing factors are more likely to be smoking during pregnancy, being poor, or being Mexican-American, the study in the October issue of Pediatrics suggested.
The finding throws a new twist into the heated debate between breast-feeding advocates and their critics.
The American Academy of Pediatrics recommends breast milk for all infants for their first year of life. However, health experts have long been concerned about tooth decay once baby teeth come in, especially for infants who nurse all night.
Researchers at the University of Rochester and New York University analyzed demographic details, dental health data and infant feeding information from 1,576 toddlers whose families participated in the 1999-2002 National Health and Nutrition Examination Survey.
Among those toddlers, 27.5 percent had had at least one tooth that had been filled or pulled because of a cavity. One in ten had severe early childhood caries, the disease that causes cavities. Just over 40 percent of the children in Mexican-American families had at least one cavity. Among children living below the federal poverty level, 41.3 percent had at least one cavity, and 18.6 percent had severe early childhood caries. Children born to mothers who were 19 or younger were also at increased risk of early childhood cavities.
The study began as an effort to understand the relationship between breast-feeding and toddlers' oral health, but the analysis uncovered more powerful risk factors.
To some degree, the data shows that breast-feeding is not protective against caries, said study author Hiroko Iida, because other factors negate the positive effect of breast-feeding. Iida is a dental public health resident at the Bureau of Dental Health, New York State Department of Health.
"Breast-feeding was associated with 40 percent reduced risk for early childhood caries until we threw factors such as poverty status, maternal age at child's birth, and maternal prenatal smoking in the analyses," he explained. Additionally, breast-fed Mexican-American children and breast-fed poor children were more likely to have cavities than other children, even when compared to those who were not breast-fed.
The concern over breast milk and cavity risk was corroborated in part by a 2005 study in rats that showed that human breast milk is more likely than cow's milk to encourage cavities.
Pediatrician and breast-feeding advocate Dr. Ruth Lawrence, a co-author of the animal study, acknowledged that the results fueled the fire of those in opposition to night nursing.
Letting a baby sleep with a bottle of anything other than plain water carries a greater risk of encouraging cavities than night nursing, said Lawrence, who says she would use the current study to reassure nursing mothers.
However, American Academy of Pediatric Dentistry (AAPD) spokesman Paul Casamassimo was more cautious.
"The literature in general is not clear in a relationship between breast-feeding and dental caries, but reports and a few studies have found relationships," he said.
Although the AAPD does not have a policy statement about breast-feeding, Casamassimo said the academy tries to educate parents to minimize the risk of cavities from any food or beverage.
Breast-feeding aside, Iida argued that pediatric dentists and public health practitioners should direct oral health efforts toward parents in low-income households, smoking mothers and Mexican-American households.
Casamassimo argued that the correlation between poverty and increased risk of cavities is well known and may explain, in part, the increased risk for Mexican-American children as well.
"The poverty correlation with caries is longstanding, consistent and believed to reflect a combination of lack of health knowledge, limited access to care, poor diet, perhaps poor prenatal care, and inadequate self-care," said Casamassimo. "Simply being Mexican-American reflects the fact that they are often among our poorest, and thus reflect the above factors."
Maternal smoking was also strongly tied to cavities risk in infants, but the analysis did not offer insight into the root of that relationship.
"As the [study] author points out, mothers tend to smoke before, through and after pregnancy, and thus the child may be poorly developed in utero and during early life, leading to increased risk for caries," said Casamassimo, who suggested that smoking may affect the child's immune system or possibly support bacteria in a mother's mouth that can be passed on to the child. "Smoking may be a surrogate measure of some factor not necessarily noted in the study. In other words, there may be a health contribution to caries susceptibility that is not measured or even known."
Preventive dental care is important for toddlers, said Iida, as the data shows cavities can grow as soon as there are teeth. One in 10 of the 2-year-olds in the study already had a cavity. Among the 5-year-olds, nearly half (44 percent) had had at least one cavity.
More information
For more about healthy teeth for children, visit the American Academy of Pediatric Dentistry.
